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The Potential of Plants as Treatments for Venous Thromboembolism
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Lilitha L. Denga, Namrita Lall
The coagulation cascade (Figure 17.2) is initiated when TF forms a complex with the activated serine protease, coagulation factor VII (FVIIa). The tissue factor and activated coagulation factor VII (TF-FVIIa) complex is a potent activator of coagulation because it activates the downstream substrates, coagulation factors IX (FIX) and X (FX), which become activated coagulation factors IX (FIXa) and X (FXa), respectively (Smith, Travers, and Morrissey 2015). The small amount of FXa, then converts initial amounts of prothrombin (FII) to thrombin (FIIa). Thrombin is a serine protease that is responsible for the amplification of the coagulation cascade and conversion of fibrinogen to fibrin in the intrinsic pathway (Brass 2003).
Cardiac Disease in Diabetes Mellitus
Published in Jack L. Leahy, Nathaniel G. Clark, William T. Cefalu, Medical Management of Diabetes Mellitus, 2000
Debasish Chaudhuri, William E. Hopkins
Platelet aggregation plays a key role in the development of intraluminal thrombus, and heightened platelet adhesiveness and aggregability increases the risks of an acute coronary event. Several studies have shown platelet hyperaggreg- ability in DM. Also, there is a higher proportion of activated platelets in the which the degree of hyperglycemiacirculation of diabetics, even in the absence of an ongoing acute coronary syndrome. Increased levels of coagulation factor VII and of fibrinogen have been demonstrated in patients with DM and appear to decrease with tight glycemic control. Fibrinogen has an independent correlation with increased risk of CAD.
Anti-inflammatory, Anti-allergic, Antipyretic, Antinociceptive, Antithrombotic, and Anti-coagulant Activities of Seaweeds and their Extracts
Published in Leonel Pereira, Therapeutic and Nutritional Uses of Algae, 2018
The blood coagulation system consists of cellular elements (blood platelets, white cells, to some extent red cells, and microvascular remnants or microparticles), coagulation enzymes, proteins cofactors, and several anticoagulant proteins (Spronk et al. 2003). The mechanism of blood coagulation is based on the enzyme cascade divided in the intrinsic, extrinsic, and common pathway, where a series of coagulation factors promote the formation of the end-product fibrin (Spronk et al. 2003, Wijesekara et al. 2011). As it can be concluded from Fig. 10.2, during the intrinsic pathway activated Stuart-Prower factor (X) can also be activated by the extrinsic pathway. Firstly, the intrinsic cascade begins with the formation of primary complex of collagen by high molecular weight kininogen (HMWK), prekallikrein, and Hageman factor (XII). During the activation, the single-chain protein of the native Hageman factor is divided into two chains of different molecular weights (28 kDa and 58 kDa). However, both chains remain linked by a disulfide bond. The 28 kDa light chain contains the active site, and this molecule is called activated Hageman factor (XIIa), which can activate plasma thromboplastin antecedent (PTA) or antihemophilic factor—C (XI). Further, HMWK, known as Fitzgerald factor, binds to the factor XI, and in the presence of Ca2+ ions, it facilitates the activation process of factor XIa. This factor XIa activates Christmas factor, plasma thromboplastin component (PTC), or antihemophilic B factor (factor IX) in the reaction requiring Ca2+ ions, factor VIII, and phospholipids. Antihemophilic factor VIII is obviously an essential factor for this step of coagulation cascade, and its deficiency is associated with hemophilia A, while the deficiency of factor IX relates to hemophilia B (Adelson et al. 1963). Activated IXa factor further activates StuartPrower factor (X) to factor Xa; and factor X is the first molecule of the common pathway of coagulation cascade. The extrinsic pathway could be considered as an alternative way of the activation of factor X in the cooperation with two main components—tissue factor (TF) and factor VII. Blood coagulation factor VII, formerly known as proconvertin, belongs to the serine protease enzyme class, and its main role in extrinsic pathway is to initiate the coagulation process in conjunction with TF.
Acute promyelocytic leukemia presenting as recurrent venous and arterial thrombotic events: a case report and review of the literature
Published in Journal of Community Hospital Internal Medicine Perspectives, 2021
Kira MacDougall, Divya Chukkalore, Maryam Rehan, Meena Kashi, Alexander Bershadskiy
Recent studies have reported leukemic pro-myelocytes in APL to have an abnormally high expression of annexin II receptor, a phospholipid-binding protein[10]. Annexin II receptors bind tissue plasminogen activator and plasminogen and increases plasmin generation by a factor of 60, therefore leading to increased fibrinolysis[11]. Additionally, the pathway of non-specific proteolysis has also been shown to lead to increased bleeding tendency in patients with APL [12,13]. The PML-RARα fusion gene in APL cells can induce tissue factor (TF) expression, which is an essential integral membrane glycoprotein expressed in various cells[14]. Under normal circumstances, TF serves as an initiator in coagulation pathways via interaction with coagulation factor VII (F VII) and its activated form (F VIIa) and plays a primary role in both normal hemostasis and thrombosis. [15] However, in pathologic conditions such as AML, TF is often expressed at a relatively high levels by monocytes, macrophages and endothelial cells, thereby initiating a series of enzymatic reactions resulting in enhanced clot formation and vascular sealing. [16]
Current and emerging pharmacotherapy for chronic spontaneous Urticaria: a focus on non-biological therapeutics
Published in Expert Opinion on Pharmacotherapy, 2021
Kam Lun Hon, Joyce T. S. Li, Alexander K.C. Leung, Vivian W. Y. Lee
Different biological processes such as autoimmunity, inflammation, coagulation, and auto-allergy are involved in basophil and mast cell degranulation [63]. Some CSU patients showed eosinophil-associated activation of the tissue factor pathway of coagulation cascade [63]. Studies also found marked increase of plasmatic markers of thrombin generation, such as prothrombin fragment 1 + 2 (F1 + 2), activated blood coagulation factor VII (FVIIa), and thrombin-antithrombin complex, especially during severe exacerbations in CSU patients [64–67]. Fibrinolysis causes an increase in D-dimer, which correlates with CSU severity [68]. A study detected elevated levels of fibrinogen/fibrin degradation products and D-dimer from fibrinolysis in CSU patients [69]. Plasma C-reactive protein levels parallel the increase in plasma markers of thrombin generation and fibrinolysis, suggesting an association between inflammation and coagulation activation in the pathogenesis of CSU [64,68].
Current strategies for hemostatic control in acute trauma hemorrhage and trauma-induced coagulopathy
Published in Expert Review of Hematology, 2018
Michael Caspers, Marc Maegele, Matthias Fröhlich
The interest in the use of recombinant activated coagulation factor VII (rFVIIa) for hemostatic control in bleeding trauma patients has consistently been declining over the past years after the results of the CONTROL trial have been published [59]. Several other but retrospective studies from the military and civil setting indicated a reduction in transfusion requirement after rFVIIIa treatment but there is clear lack of prospective reliable data from large patient cohorts that would support a survival benefit as a result of its use in the context of trauma [60,61]. The administration of rFVIIa is currently not recommended as a standard procedure and only indicated as rescue therapy if major bleeding and coagulopathy persists after failure of best practice to control bleeding and exsanguination [17,46].